The present invention relates to injection molding and relates in particular to methods and machinery for recovering and collecting molded articles in continuous fashion.
In modern high speed mass production of molded articles, it is important to maintain rapid molding cycles at uniform rates to maintain product quality.
It is also desirable to recover molded articles quickly with a minimum interference with the mold cycle and without prolonging the cycle time.
In the interest of efficient and economical packaging of the molded articles, it is desirable to receive, recover and collect articles continuously where the disposition of each article or its orientation is uniform.
Articles so received and so arranged lend themselves to high speed automatic packaging machinery and similar processes.
In contrast, where the articles are received or recovered in random fashion, it is frequently necessary to expend a great amount of manual effort to arrange the molded articles into a uniform, orderly orientation before introduction to a packaging station or to other processing operations.
Prior art devices and methods have succeeded in solving this problem but frequently at the expense of prolonging the molding cycle. In addition, such prior art devices are manufactured of close tolerance piece parts which require considerable maintenance and frequent parts' replacement, because the said devices must be accurately positioned to receive molded articles upon ejection.
A prior art apparatus of this class operable to recover molded articles with uniform orientation in continuous fashion is shown and described in U.S. Pat. No. 3,910,740, issued Oct. 7, 1975 to H. Rees, entitled "Injection-Control System for Injection Molding Machine" and assigned on its face to Husky Injection Molding Systems, Ltd.
In the '740 patent and in the embodiment of FIGS. 1-5, a pair of generally parallel rods 22a and 22b are traversed toward and away from a mold cavity in synchronism with the opening and closing of the mold cavity driven by the cam and follower arrangement shown in FIG. 5. When the mold cavity is closed the parallel rods are expanded and are disposed in the position of FIG. 2. Upon opening the mold the elements 22a and 22b are drawn to the edge of the molded article 21 providing a track for guiding the articles downwardly along a vertical path to a convenient receptacle.
In usual and customary fashion, the molded articles are removed from the mold wall 19 by the stripper plate 16.
In the '740 device, mold time is lost while the articles are provided an interval of time to drop vertically by gravity. In addition, frequently the articles hang up in the track and must be advanced or urged along with a jet of air.